Apparatus for spinning artificial silk with greater take-up speed



Sept. 4, 1934. J. J. s'rocKLY ET AL APPARATUS FOR SPINNING ARTIFICIAL S Filed May 15. 1930 ILK WITH GREATER TAKE-UP SPEED Patented Sept. 4, 19345 :PATENT oF FicE APPARATUS FOR SPINNING ARTIFICIAL SILK WITH GREATER TAKE-UP SPEED Johann Joseph' Stiickly and August Briitz,

Teltow- Seehof, Germany, assignors to North American Rayon Corporation, New York, N. Y.

Application May15, 1930, Serial No. 452,700 1 In Germany May 15,1929.

9 Claims.

When manufacturin g artificial silk with liquid precipitating baths, such as the manufacture of viscose silk, copper-ammonia silk, acetate silk,

etc., it has been the-practice, until lately, touse :5 low take-up speeds of about 30-50 m. per minute.

In order to utilize the spinning machines to better advantage, many experiments were attempted in order to increase this speed, and actual speeds or" 60 and even 70 m. per minute have been reached.

m A number of unforeseen diificulties arose through the use of a greater speed. For example, it was found that, with a relatively great take-up speed, the newly spun thread, consisting of a number of elementary filaments, coming out of the spinning bath carries with it considerable quantities of the bath solution. The spinning solution carried by the thread becomes so great with an increased take-up speed that the spinning bath trough will be drained empty within a very short time. The

take-up thread carries with it a column of liquid which may be 5, 10 or even times thicker than the thread itself. The large quantity of solution is carried-on to the take-up device, the spool, the roller, the transmissionroll, or the stretching v roller and is splattered'all over the spinning room owing to the great speed of these'devices, damaging the machine and endangering the operator. The solution is not carried by the thread in regular quantities but by jolts and in wave-like .movements. This will have an intermittent and irregular effect on the entire thread with a chemical as well as a mechanical influence. The quantitles of solution carried by the thread also affect the single filaments, in an irregular way, in-

asmuch as the outside filaments of the thread are stretched more by the weight of the solution and are partly dragged back to the bath; or, if the spinning is done in an oblique direction, the thread becomes fan-shaped and the filaments are deviated from the main thread. All these irregular, chemical and mechanical effects on the whole thread and on the single filaments further influence the solidity and the dyeing qualities of the finished yarn and the filaments are often broken,

, which causes an inferior quality of the finished product.

After this had been observed it was found that these difiiculties could be overcome if it were possible to do away with the carrying of this solution of the bath at an increased take-up speed. Tests were made relative to wiping off the solution from the thread, but Without success.

It has now been found that much less solution is carried by the thread if a round opening or ring-like thread guide device is placed near the kit spinning bath surface through whichthe thread has to pass. Thering-like thread guide device must be either on the surface of the spinning: bath or a little below the surface, but it can also be fixed a little above thesurface. If the device is placed too far away from the surface of the bath, the thread carries the solution up to this device, and the desired efiect will then not be at-. tained. I

The accompanying drawing illustrates a suit- 65, able arrangement whereby We obtain our new result. In the drawing, the figure shows an e1e-, vation partly in vertical section of an apparatus in operation, the guide 6 being also illustrated in plan.

From the spinning trough the thread leaves the spinnerette l in a vertical direction and is carried through the threadguide device 5 which is close to the surface of the spinning bath 2, is fixed and ring-shaped and is positioned at right angles to the direction of the thread. The ring-shaped threadguide' device 5 is a bent glass rod about 6 thick and with an opening of about 4 mm. diameter. The thread leaves this device in a vertical direction and passes through the second similarly constructed ring-shaped and fixed thread guide device 6, from whence it is taken up by the rotating spool 3 through the crossing or thread distributing device 4. This take-up deice may be either a spinning spool of an ordinary spool spinning machine, or a roller of a socalled roller spinning machine, or a transmission roll of a so-called centrifuge spinning machine, or any other take-up device. If the rotating device 3 does not take up the thread its-elf, of course the crossing device 4 may be eliminated,

By using the above arrangement the principal amount of the spinning bath solution carried with the thread may be retained in the bath. The effect is still more thorough if a second fixed and circular threadguide is inserted in the air space between the above mentioned first ring-like threadguide device and the rotating take-up spool. This second device has two effects, first it eliminates the reaction of the thread crossing 1 on the smooth running of the thread through the first circular threadguide device, and second, it retains any remaining spinning bath solution carried'by the thread. As a matter of fact, the second thread guide device may be of the same design as the first one.

If the thread is spun on the take-up spool in a direction vertical to the spinning bath, it will be of advantage to arrange the two above mentioned thread guide devices and the spinnerette in a vertical position one above the other.

In order to obtain the best results, care should be taken regarding the form and size of the circular openings of the thread guide device. In order to obtain a good efiect the most suitable size of the circular openings for normal rayon threads will be from 2 to '7 mm. The size depends upon the total denier of the spun threads and with large deniers of 500, 1000 or more, the circular opening may be still larger. On the other hand the shape of the ring-like thread guide device is to be taken into consideration. For instance, when using round rods they have to be of a certain thickness. With rings made 'of very thin rods i. e. of 1, 2 and 3 mm., the effect according to the process is only moderate and will become better if sticks having a thickness of 4 mm. or more are selected.

We claim:

1. An apparatus for spinning artificial silk, comprising a spinning nozzle within a precipitating bath, a take-up device adapted to draw the thread from the nozzle substantially without changing its direction, and means positioned substantially at the surface of the liquid in the proximity of but out of contact with the thread for retarding the flow of precipitating liquid with the thread.

2. An apparatus for spinning artificial silk, comprising a spinning nozzle within a precipitating bath, 'a take-up device adapted to draw the thread from the spinning nozzle in a substantially vertical direction, means for distributing 35 ,liquid retarding means positioned vertically above said first liquid retarding means and slightly above the surface or" the liquid.

3. An apparatus for spinning artificial silk, comprising a spinning nozzle within a precipitating bath, a take-up device adapted to draw the filaments from the spinning nozzle substantially without changing their direction, means for retarding the flow of precipitating liquid with the thread positioned slightly beneath the surface of the precipitating bath and in the proximity of but out of contact with the thread.

4. An apparatus as defined in claim 1 including a thread distributing device for distributing the thread upon the take-up device and a second liquid retarding means between the thread dis tributing device and the means for retarding the flow of the precipitating liquid.

5. An apparatus as defined in claim 3 including a thread distributing device for distributing thread upon the take-up device and a second liquid retarding means between the thread distributing device and the surface of the precipitating bath.

6. An apparatus as defined in claim 1 in which the means for retarding the flow of precipitating liquid is a thread guide surrounding the thread.

7. An apparatus as defined in claim 3 in which the means for retarding the flow of precipitating liquid is'a thread guide surrounding the thread.

8. An apparatus as defined in claim 1 including a movable thread distributing device for distributing the thread upon the take-up device and a fixed thread guide between the thread distributing device and the means for retarding the flow or" the precipitating liquid, said fixed thread guide being adapted to effect a smooth running of the thread through the means for retarding the fiow of the precipitating liquid.

9. An apparatus as defined in claim 3 including a movable thread distributing device for distributing thread upon the take-up device and a fixed thread guide between the thread distributing device and the surface of the precipitating bath, said fixed thread guide being adapted to effect a smooth running or the thread through the means for retarding the flow of precipitating liquid with the thread.

JOHANN JOSEPH s'rocKLY. AUGUST nn'o'rz. 

